scholarly journals Гальваномагнитные свойства в анизотропных слоистых пленках на основе халькогенидов висмута

2021 ◽  
Vol 55 (12) ◽  
pp. 1119
Author(s):  
О.А. Усов ◽  
Л.Н. Лукьянова ◽  
М.П. Волков
Keyword(s):  
Low Temperatures ◽  
High Surface ◽  
Surface States ◽  
Surface Concentration ◽  
Dirac Fermion ◽  
Quantum Oscillations ◽  
Strong Magnetic Fields ◽  
High Surface Concentration ◽  
Comparison Of The Results ◽  
Tunnel Spectroscopy

In anisotropic layered films of a multicomponent n-Bi1.92In0.02Te2.85Se0.15 solid solution in strong magnetic fields from 2 to 14 T at low temperatures, quantum oscillations of magnetoresistance associated with surface states of electrons in 3D topological insulators were studied. From the analysis of the spectral distribution of the amplitudes of quantum oscillations of magnetoresistance, the main parameters of the Dirac fermion surface states are determined. A comparison of the results with the data obtained by the method of scanning tunnel spectroscopy was carried out. It is shown that a high surface concentration determines the contribution of the Dirac fermion surface states to the thermoelectric properties of n-Bi1.92In0.02Te2.85Se0.15.

A New Model of Tail Diffusion of Phosphorus and Boron in Silicon

1985 ◽  
Vol 52 ◽  
Author(s):  
Frederick F. Morehead ◽  
R. F. Lever
Keyword(s):  
Concentration Profile ◽  
Process Simulation ◽  
Low Temperatures ◽  
High Surface ◽  
Surface Concentration ◽  
Transient Effects ◽  
Phosphorus Diffusion ◽  
High Surface Concentration ◽  
Conventional Models ◽  
Normal Processing

ABSTRACTIt is well known that high surface concentration phosphorus diffusion leads to deeply penetrating “tails” in its concentration profile. At 700 °C the tail diffusivity exceeds that of low concentration phosphorus by a factor of a thousand. Less spectacular, but very significant tailing also affects tioron, making the conventional models contained in commonly available process simulation programs quite inaccurate for boron diffusions with high surface concentrations. We show that the observed tailing can be accounted for by a model whose central assumption is the local equality of dopant and oppositely directed defect fluxes. As predicted by the model, the effect is greatest for normal processing at low temperatures for high surface concentrations. It is minimal for the high temperatures of rapid thermal annealing and unrelated to transient effects.

Magnetic Quantum Oscillations from Surface States of Bi Nanowires

2011 ◽  
Vol 1350 ◽  
Author(s):  
L. A. Konopko ◽  
T. E. Huber ◽  
A. A. Nikolaeva
Keyword(s):  
Single Crystal ◽  
Low Temperatures ◽  
Surface States ◽  
Charge Carriers ◽  
Quantum Oscillations ◽  
Wide Range ◽  
Spin Orbit Interactions ◽  
Conducting Tube ◽  
Magnetic Quantum Oscillations ◽  
Strong Spin

ABSTRACTIn this work, we report the results of studies of the transverse magnetoresistance (MR) of single-crystal Bi nanowires with diameter d<80 nm. The single-crystal nanowire samples were prepared by the Taylor-Ulitovsky technique. Due to the semimetal-to-semiconductor transformation and high density of surface states with strong spin-orbit interactions, the charge carriers are confined to the conducting tube made of surface states. The non monotonic changes of transverse MR that are equidistant in a direct magnetic field were observed at low temperatures in a wide range of magnetic fields up to 14 T. The period of oscillations depends on the wire diameter d as for the case of longitudinal MR. An interpretation of transverse MR oscillations is presented.

A Steady-State Model for Coupled Defect Impurity Diffusion in Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
F. F. Morehead ◽  
R. F. Lever
Keyword(s):  
Steady State ◽  
High Surface ◽  
Local Equilibrium ◽  
Surface Concentration ◽  
Extended Model ◽  
High Concentration ◽  
Steady State Model ◽  
High Surface Concentration ◽  
Phosphorus In Silicon ◽  
Diffusion Profiles

AbstractWe extend our earlier model which was proposed to explain tails in the diffusion profiles of high concentration boron and phosphorus in silicon. Our quasi-steady-state approach is generalized here to include both vacancies (V) and interstitials (I) at equivalent levels. I-V recombination is regarded as near local equilibrium, occurring through reactions of the defects with defect-impurity pairs. This approach leads to the well-known plateau, kink and tail in high surface concentration P diffusions in Si and to the less well recognized tails in B as well. Our extended model, in its simplest form, allows a more complete and less restrictive treatment of Au diffusion in Si. An important advantage is the direct inclusion of these defect-impurity interactions and the resulting gradients in the defect concentrations.

Effect of Microalloying with Ti or Cr on the Corrosion Behavior of Al-Ni-Y Amorphous Alloys

CORROSION ◽  
10.5006/2451 ◽  
2017 ◽  
Vol 74 (1) ◽  
pp. 66-74 ◽  
Author(s):  
L.M. Zhang ◽  
A.L. Ma ◽  
H.X. Hu ◽  
Y.G. Zheng ◽  
B.J. Yang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Amorphous Alloys ◽  
Diffusion Mechanism ◽  
High Surface ◽  
Control Sample ◽  
Surface Concentration ◽  
Passive Films ◽  
High Surface Concentration

The effect of microalloying with Ti or Cr on the corrosion behavior of Al-Ni-Y amorphous alloys in 0.1 M NaCl solution was studied by potentiodynamic polarization, Mott-Schottky, and x-ray photoelectron spectroscopy techniques. Microalloying with Ti or Cr could greatly improve the corrosion resistance of Al-Ni-Y amorphous alloys. A high surface concentration of Ti or Cr in the passive films was detected, which should be responsible for the improved corrosion resistance compared to the control sample. The possible process of Ti or Cr involved in the passive films was proposed in terms of the point defect model and the vacancy diffusion mechanism. Furthermore, the effect of Ti was stronger than Cr because of the higher film resistance as well as the higher surface concentration. The different passivation abilities and atomic radiuses between Ti and Cr were presented to explain the better microalloying effect of Ti compared to Cr.

scholarly journals Термоэлектрические и гальваномагнитные свойства слоистых пленок n-Bi-=SUB=-2-x-=/SUB=-Sb-=SUB=-x-=/SUB=-Te-=SUB=-3-y-=/SUB=-Se-=SUB=-y-=/SUB=-

2019 ◽  
Vol 53 (5) ◽  
pp. 626
Author(s):  
Л.Н. Лукьянова ◽  
О.А. Усов ◽  
М.П. Волков
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Low Temperatures ◽  
Bulk Material ◽  
Surface States ◽  
Dirac Fermions ◽  
Thermoelectric Efficiency ◽  
Strong Magnetic Fields ◽  
Topological Surface ◽  
Magnetoresistance Oscillations

n nanostructured layered films of topological thermoelectrics n-Bi2−xSbxTe3−y Sey , thermoelectric properties in the temperature range of 4.2−300K and magnetoresistance oscillations in strong magnetic fields at low temperatures were studied. It is shown that thermoelectric efficiency in the layered n-Bi2−xSbxTe3−y Sey films increases as compared with bulk material due to both an increase in the Seebeck coefficient at the temperatures below room one, and a decrease in thermal conductivity and weakening of its temperature dependence. From the analysis of magnetoresistance oscillations, the parameters of topological surface states of Dirac fermions were determined and their influence on thermoelectric properties was estimated.

Fabrication of Ultra-Shallow P+-N and N+-P Junctions by Diffusion From Selectively Deposited, Ion-Implanted and In-Situ Doped Si0.7Ge0.3

1993 ◽  
Vol 303 ◽  
Author(s):  
D.T. Grider ◽  
M.C. ÖztÜrk ◽  
J.J. Wortman ◽  
G.S. Harris ◽  
D.M. Maher
Keyword(s):  
High Surface ◽  
Chemical Vapor ◽  
Surface Concentration ◽  
Shallow Junctions ◽  
High Surface Concentration ◽  
Diffusion Source ◽  
Ultra Shallow Junctions ◽  
P Type ◽  
Ion Implanted

ABSTRACTSelectively deposited Si0.7Ge0.3 has been investigated as a potential diffusion source for fabricating ultra-shallow junctions in Si. Rapid thermal chemical vapor deposition (RTCVD) was used to selectively deposit Si0.7Ge0.3 on Si using SiH2C12, GeH4, and H2. Both ionimplanted and in-situ doped Si0.7Ge0.3 were considered as a diffusion source for fabricating ultra-shallow junctions. In-situ doping was achieved with B2H6 and PH3 for p-type and n-type doping, respectively. Boron and phosphorus diffusion in ion-implanted Si0.7Ge0.3 was investigated and modeled using SSUPREM4. Diffusion from implanted and in-situ doped Si0.7Ge0.3 in Si was also studied and modeled. Boron diffusivities in Si0.7Ge0.3 were found to be approximately 10 times greater than in Si, while phosphorus diffusivities were over 100 times greater in Si0.7Ge0.3. The faster dopant diffusivities in Si0.7Ge0.3 allow high surface concentration, abrupt diffusion profiles to be formed in Si. Gated, p-n junction diodes with junction depths as shallow as 140Å were fabricated and tested to study the quality of the diffusions from Si0.7Ge0.3.

Fluorescent Reactive Core–Shell Composite Nanoparticles with A High Surface Concentration of Epoxy Functionalities

2008 ◽  
Vol 20 (1) ◽  
pp. 317-325 ◽  
Author(s):  
Volodymyr Tsyalkovsky ◽  
Viktor Klep ◽  
Karthik Ramaratnam ◽  
Robert Lupitskyy ◽  
Sergiy Minko ◽  
...  
Keyword(s):  
High Surface ◽  
Surface Concentration ◽  
Composite Nanoparticles ◽  
Core Shell ◽  
High Surface Concentration ◽  
Shell Composite
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